| 摘要 |
PURPOSE:To improve the effect of relieving the elongation of optical fiber strands against tension and the effect of preventing the intrusion of water, by covering a core assemblage, which is twisted together with optical fiber cores consisting of optical fiber strands provided extermally with gellike material layers, with a gel-like material layer. CONSTITUTION:A central tensile body 1 consisting of a stainless steel wire or the like is provided as a central wire 3 of a unit, and plural optical fiber cores 4 are twisted together with an intervention 12 on the outside circumference thereof, whereby an optical fiber core assemblage 5 is formed. Each core 4 is formed by providing a gel-like material layer 13 around a strand 8 consisting of an optical fiber 6 coated externally with a primary covering layer 7 of silicone rubber or the like and providing a core protective layer 14 of nylon or the like on the outside circumference thereof. The gel-like material has no fluidity and has such nature that it does not hinder the movement of the strand 8 and its JIS hardness is roughly zero. A gel-like material layer 15 is coated on the outside circumference of the assemblage 5 so as to fill the gaps among the cores 4 and between the cores 4 and the wire 3. A protective layer 16 of the unit is provided on the outside circumference of the layer 15. |
